fix identifiers (#43)

Author: matth2k

src/circuit.rs

@@ -65,13 +65,26 @@ pub struct Identifier {
 impl Identifier {
     /// Creates a new identifier with the given name
     pub fn new(name: String) -> Self {
+        if name.is_empty() {
+            panic!("Identifier name cannot be empty");
+        }
+
         if let Some(root) = name.strip_prefix('\\') {
             return Identifier {
                 name: root.to_string(),
                 id_type: IdentifierType::Escaped,
             };
         }
 
+        // Check if first char is a digit
+        let esc_chars = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9'];
+        if esc_chars.contains(&name.chars().next().unwrap()) {
+            return Identifier {
+                name,
+                id_type: IdentifierType::Escaped,
+            };
+        }
+
         // Certainly not an exhaustive list.
         // TODO(matth2k): Implement a true isEscaped()
         let esc_chars = [' ', '\\', '(', ')', ',', '+', '-', '$', '\'', '~'];

tests/identifiers.rs

@@ -25,3 +25,13 @@ fn concat_simple_w_escaped() {
     assert_eq!(Identifier::new("\\id0_id1$".to_string()), id2);
     assert!(id2.is_escaped());
 }
+
+#[test]
+fn aig_id() {
+    let id0 = Identifier::new("1".to_string());
+    assert!(id0.is_escaped());
+    let id1 = Identifier::new("inv".to_string());
+    let id2 = id0 + id1;
+    assert_eq!(Identifier::new("\\1_inv".to_string()), id2);
+    assert!(id2.is_escaped());
+}